公开(公告)号：US11081174B2

公开(公告)日：2021-08-03

申请号：US16912719

申请日：2020-06-26

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Zhaoqiang Bai ,  Mac D. Apodaca ,  Michael K. Grobis ,  Michael Nicolas Albert Tran ,  Neil Leslie Robertson ,  Gerardo A. Bertero

IPC: G11C13/00 ,  H01L27/24 ,  H01L45/00

Abstract: A two-step SET pulse may be applied to a phase change material of a phase change memory cell in which a first lower SET pulse is applied to make the phase change material dwell at 600K to incubate nuclei near the maximum nucleation rate and then a second higher SET pulse is immediately applied to make the phase change material dwell at 720K to maximize crystal growth. Moreover, the slope of the falling edge of a RESET pulse applied prior to the two-step SET pulse may be adjusted to increase the number of nuclei (e.g., formed with a steeper falling edge) to increase SET efficiency at the expense of a more stable amorphous phase (e.g., formed with a less steep falling edge) that improves data retention.

公开(公告)号：US10943952B2

公开(公告)日：2021-03-09

申请号：US16435843

申请日：2019-06-10

Applicant: SanDisk Technologies LLC

Inventor： Federico Nardi ,  Ming-Che Wu ,  Tim Minvielle ,  Zhaoqiang Bai

IPC: H01L45/00 ,  H01L27/24 ,  G11C13/00

Abstract: The switching device includes three terminals including an inner surface, an oxide layer on the inner surface of the third terminal, and a chalcogenide pillar extending through the oxide layer and the third terminal, the pillar being in electrical communication with the first terminal and the second terminal, wherein the voltage difference between the first terminal and the second terminal changes the channel from a first state to a second state when a threshold voltage between the first terminal and the second terminal is exceeded, the threshold voltage being dependent on temperature. The third terminal is resistive and receives a control signal to apply heat to the pillar and modulate the threshold voltage. The switching device can be used to select the memory stack through the bitline and provide a nearly limitless current based on the threshold switching conduction providing avalanche current conduction through the switching device.